As mentioned above, positioning devices of this type are often used in servo track writers (STW), where the tracks for magnetizable hard disks are set up or written. In this context, a shaft, on which a swivel arm is mounted, is pivoted in the STW by a voice-coil motor or pivot drive in the positioning device. At its end, a write head is provided which is ultimately moved by the swivel motion of the shaft and is positioned in a highly precise manner, so that as many tracks as possible per unit surface area of the hard disk can be configured. The number of tracks set up per unit surface area or unit diameter (tracks per inch) is a measure of the storage capacity of hard disks. For this reason, efforts are undertaken to achieve a track allocation that is as tight as possible. For a hard disk manufacturer to be able to configure hard disks with a dense track allocation in an economical manner, it must be possible to position the swivel arm of the STW in an exact manner within a very short time (seek and settle time).
A voice-coil motor, whose stator is designed as a printed circuit board, is described in German Published Patent Application No. 196 37 953. This printed circuit board has a circuit-board conductor, which is designed to form a winding or coil unit. This coil unit is made up of a circuit-board conductor having several circuit traces, which are side-by-side and extend in parallel.
Conventional voice-coil motors and the corresponding positioning devices may have the disadvantage that their accuracy and their seek-and-settle time do not satisfy the highest standards.